Recently, the winter sport of snowboarding has experienced an explosive growth in popularity in the United States as well as other countries worldwide. Due in part to the popularity and relative infancy of this sport, snowboarding equipment is evolving at a rapid pace.
One area of substantial development is the manner in which a snowboarder is mounted to the snowboard. Unlike conventional snow skiing, both feet of the snowboarder are mounted to a single snowboard, and snowboarding boots are generally relatively soft and are both strapped atop of the snowboard in a transverse or angled manner relative the length of the board. Another significant difference between the bindings is that conventional snow skiing bindings are designed to release upon sufficient torsional forces applied to the bindings via the foot of the skier. Snowboarding bindings, on the other hand, typically only release when the snowboarder manually releases the binding. Hence, the snowboarder remains bound to the snowboard regardless of the magnitude of the fall.
The primary reason safety release bindings are considered unnecessary in snowboarding is that the twisting forces exerted on the body during a fall are more absorbed by the torso of the snowboarder rather than the individual ankles or knees. In contrast, the torsional forces associated with snow skiing experienced during a fall is more often absorbed by the ankles and knees of the skier sometimes resulting in injury.
However, snowboard related knee injuries are not uncommon, and there is an increasing concern that these manual-only releasable bindings may partially be responsible for these injuries. As a result, numerous releasable bindings have been developed which are adapted to release one or both of the snowboarders boots from the bindings upon sufficient twisting or torsional forces acting on the binding. Typical of these patented torsional release bindings are disclosed in U.S. Pat. Nos.: 4,652,007 to Dennis; 4,728,116 to Hill; and 5,145,202 to Miller.
One significant drawback for these torsional-type releasable bindings, however, is that to impact release the boot from the binding, a sufficient torsional force must be directly exerted on the binding from the boot of the snowboarder. For example, similar to snow ski bindings, release of the binding occurs when the snowboarder is forced sufficiently forward so that the forward twisting of the snowboarder releases the binding. The other way these bindings release is when the snowboarder exerts sufficient torsional forces, in a plane parallel to the snowboard, to twist the boot from the binding. Often, these torsional forces which are absorbed partially by the knees are still sufficient to cause significant injury to the snowboarder.